I wonder if the places that don't allow mobile phones will stop allowing wearing a watch as well? (especially if new models come out where it's hard to tell the difference between smart and automatic wind...) Will all the judges and lawyers have to remove their fancy watches at the court entrance? And military pilots before entering launch control? Will kids be allowed to look at their "watch" to see how much time they have left taking an exam? Etc.
Yeah, it's like when camera phones were new, or calculators with alphanumeric storage used during testing.
At first few knew about these new technologies, and users could slide by. But not forever.
So I think you're right. As more people become aware of smartwatches, more rules will emerge.